The present invention refers to formwork for pillars of the type constituted by several plates which are flat and rectangular, each of which consists of an inner flat side and an outer side provided with a transverse rib, formed by C-shaped profiles integral to the plate by its central span, the assembly position of the formwork being acquired when each of the plates is arranged with one of its longitudinal edges in even contact with an inner side of an adjoining plate, until it forms a prismatic contour closed by the inner flat sides of all the plates, each facing the other, which sets a hole intended to be taken up by the concrete of the pillar, the plates comprising a means of mutual fixing and detachable means of immobilization.
Multiple ways of carrying out formwork for pillars have been known for many years, amongst which it is possible to highlight Spanish utility model numbers 76.449, 95.410, 170.297, 170.326, U 8900526, U 9400013 and U 9500862, all of which refer to formwork particularly applicable to the construction of pillars.
In all of the embodiments described in the aforementioned models, plates, which are joined to each other by means of latches and pins, are used and these go through orifices and grooves of another plate which are fixed with tightening nuts and screws or by means of wedges inserted into the corresponding grooves.
Out of all of them, only utility model Nxc2x0 U 9500862 contemplates the possibility that the latches and pins, which are retractable, are inseparably joined to the corresponding plate.
In particular, Spanish utility model U 9500862 discloses a formwork for pillars, of the type constituted by several plates which are flat and rectangular, each of which consists of an inner flat side and an outer side provided with a transverse rib, formed by C-shaped profiles integral to the plate by its central span, the assembly position of the formwork being acquired when each of the plates is arranged with one of its longitudinal edges in even contact with an inner side of an adjoining plate, until it forms a prismatic contour, closed by the inner flat sides of all the plates, each facing the other, which sets a hole intended to be taken up by the concrete of the pillar, the plates comprising a means of mutual fixing and detachable means of immobilization, whereby the aforesaid means of mutual fixing are constituted by a longitudinal series of hinges, fixed to the edge of the plate intended to be in contact with the inner flat side of the adjoining plate, and by a corresponding longitudinal series of orifices, evenly distributed in transversal direction over the inner side, in such a way that the assembling of the formwork only requires to face the hinges of each plate to the corresponding orifices of each series of the adjoining plate and insert the hinges into the orifices.
The object of U 9500862 contributes the important advantage that it is impossible to lose them in successive utilizations of the plate. In spite of this, the object of said utility model Nxc2x0 U 9500862 shows certain drawbacks which make its application fairly annoying, such as, for example, the fact that the prior and individual adjustment of all the pins must be carried out when the plate is coupled to another adjoining one and that the pins have to be adjusted by means of a nut and subsequent tightening of same.
All of the drawbacks mentioned, are completely eliminated in the formwork for pillars object of the present invention which is characterized in that the said orifices are oblong and in that the detachable means of mutual immobilization of the plates are constituted by a through hole made in the shaft of each hinge and by a sliding element provided with a wedge-shaped end arranged with the possibility of transversal movement and with adjustment in the inside of the xe2x80x9cCxe2x80x9d-shaped profiles, said means of immobilization being operative when the wedge of one of the plates is inserted in the hole of the hinge shaft of the adjoining plate, in such a way with that they prevent the unwanted separation of the plate with respect to the adjoining one.
The formwork object of the present invention also allows for a considerable reduction in the assembly time of formwork, by noticeably diminishing the coupling and fixing time of one plate to another, as it is not necessary to face the bolts one to one nor fix them with nuts. An additional advantage is also achieved which consists of the fact that the coupling parts, such as nuts or tightening spanners, cannot be lost either.